How can I prevent Drupal from saving the user's initial email address? (init in the users_field_data table)?

Question

I am trying to reduce the amount of PII (personally identifiable information) that my site collects.

When a user registers an account, by default, that email address is saved twice in the users_field_data table-- once to the mail column, and again to the init column. This may be useful for some sites, but as far as I know core never uses the init value for anything, and so I would like to prevent any value being saved to init.

Answer 1

Looking into this, the initial email is only collected automatically if the user registers using the registration form; decoupled registrations do not have init set.

I know the general recommendation is not to patch core, but in this case it's a single line:

diff --git a/core/modules/user/src/RegisterForm.php b/core/modules/user/src/RegisterForm.php
index 0a4da2dcf1..cf2fdd159b 100644
--- a/core/modules/user/src/RegisterForm.php
+++ b/core/modules/user/src/RegisterForm.php
@@ -81,7 +81,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
     $form_state->cleanValues();
 
     $form_state->setValue('pass', $pass);
-    $form_state->setValue('init', $form_state->getValue('mail'));
+    // $form_state->setValue('init', $form_state->getValue('mail'));
 
     parent::submitForm($form, $form_state);
   }